I’ve a number of legacy machines which need virtualising with Vmware Vsphere5. Mainly they are old servers running software and websites that cannot be ported to modern OS’s and hardware. I thought to get the ball rolling, I’d migrate our old Cacti server in. The process will be done in a few stages;
- Create a new VM in Vsphere
- Boot into the FreeBSD 9.0 LiveCD
- Setup the server for SSH
- Prepare the storage
- Dump and Restore the data over an SSH tunnel
- Final adjustments
Create a new VM in Vsphere
I’m using Vmware Vcenter with my ‘head’ servers, but you can do this with the Vsphere client just as well. Select the size of disk needed – i checked to see if i could reduce the overhead with a ‘df -h’ on the source server. Add the FreeBSD 9.0 CD and ensure its connected when the VM is powered on.
Boot into the LiveCD
Let the installed run until you get a blue screen inviting you to create a LiveCD or carry on with an install. Choose LiveCD, and login as root. there is no password at this point, and as the OS is on a read only disk (ie the CD) it can’t be changed – yet. Before we go much further we need to increase the size of the /tmp partition which by default is very small and is a RAM disk. To do this we’ll drop the mount and create a larger RAM disk:
umount /tmp mdmfs -M -s256m md1 /tmp
Setup the server for SSH
Firstly, to enable us to contact the server as root we need to make the /etc partition writable. This is done with:
mkdir /tmp/etc mount_unionfs /tmp/etc /etc
Edit the sshd config file and permit root login:
ee /etc/ssh/sshd_config ==/== PermitRootLogin yes ==/==
Now start the daemon:
/etc/rc.d/sshd onestart
Now add a root password with the passwd command. Next we’ll add some IP address information. On the vsphere5 freebsd install the driver is the em0 driver, so:
ifconfig em0 inet 192.168.1.90 netmask 255.255.255.0 up route add default 192.168.1.1
No we can ssh to the vm and stop all the annoying typing at the console.
Prepare the Storage
This can be done in one of 2 methods; the complicated way and the easy way. I chose the easy way which is to use sysinstall.
Type ‘sysinstall’
Select configure, then Fdisk
Were using the whole disk (press A) and the ‘W’ to write, then the boot manager screen follows:
Then back to the config menu to select ‘Label’:
First create the swap partition (4G for this server) with ‘C’, the ‘4G’ then ‘Swap’. After that press ‘C’ again and accept the rest of the disk, select ‘File system’ and make the mount point ‘/’ (root). At this point arrow down to highlight the root partition and change the mount point using the ‘M’ to ‘/mnt’. Now we are ready to go to the source server…
Dump and Restore via an SSH tunnel
Assuming there are 3 partitions that are needed (/, /var, /usr) them we need to do 3 of these:
dump -0 -L -f - / | ssh -l root 192.168.1.90 "cd /mnt ;restore -rf -" dump -0 -L -f - /var | ssh -l root 192.168.1.90 "cd /mnt/var ;restore -rf -" dump -0 -L -f - /usr | ssh -l root 192.168.1.90 "cd /mnt/usr ;restore -rf -"
There are a few things to note here on the dump command:
-0 Full backup -L The system is live so use a snapshot -f - send the output to stdout
On the restore
-r rebuild filesystem -f - output to stdout
It’s very important that the restore is done from the destination partition, hence the ‘cd xxx;’ in the restore command.
Final Adjustments
We need to modify the ‘/etc/fstab’ file to ensure the device names are correct and the number of partitions is correct. In my example i’ve moved from a multi partition setup with separate /var, /usr etc to a single root partition. My old fstab looked like this:
# Device Mountpoint FStype Options Dump Pass# /dev/amrd0s1b none swap sw 0 0 /dev/amrd0s1a / ufs rw 1 1 /dev/amrd0s1e /tmp ufs rw 2 2 /dev/amrd0s1f /usr ufs rw 2 2 /dev/amrd0s1d /var ufs rw 2 2 /dev/acd0 /cdrom cd9660 ro,noauto 0 0
which I modified (on the VM so its ‘/mnt/etc/fstab’) to this:
# Device Mountpoint FStype Options Dump Pass# /dev/da0s1b none swap sw 0 0 /dev/da0s1a / ufs rw 1 1 /dev/acd0 /cdrom cd9660 ro,noauto 0 0
In addition, the network cards will probably have different device names, but in my case they both used ’em0′, however if you need to change them, edit ‘/mnt/etc/rc.conf’
Then reboot!
Footnotes
The MySQL instance would not start on my VM, but i found this was because the /tmp volume had incorrect permissions. I change this with:
chmod 777 /tmp
